A miniature electret microphone includes a housing, a back platediaphragm assembly, an integrated circuit and a filter circuit. Systems and methods are disclosed for generating a foreground image layer and mask layer, which enables high-quality and high-ratio document compression. The optomechanical element is positioned adjacent and between said first and second components such that a portion of the optomechanical element is exposed to a leakage light when the first and second components are misaligned. A second dielectric layer is formed over the stop layer. Then, each binary component of the binary product is multiplied with a respective one of the stored 2^i mod values to obtain a plurality of intermediate mod value.